Valve for rock drills



March 11, 1930. E. B. LEAR VALVE FOR ROCK DRILLS Filed Dec. 14, 1928 IN V EN TOR. @Zi BY HIS A TTORNEY Patented Mar. 11, 1930 51 j UNITED STATES PATENT OFFICE EARL B. LEAR, OF PHILLIPSBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL-RAND COM- PANY, OF J JERSEY-CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY new FOR noon 'DRILLS Application filed December 14, 1928. Seri a1 No. 325,952.

* This invention relates to'r'ock drills, but more particularly to a distributing valve for fluid actuated rock drills of thehammer YP v 5 One object of the invention is to obtain a rapid and positive action of the'valve for distributing the pressure fluid to'theends of the cylinder. I j

Other objects will be in-part obvious and in part pointed out hereinafter; In'the'drawings illustrating the invention and I in which similar reference characters refer to similar parts, I I 1 Figure 1 is a sectional elevation of a rock 5 drill equipped witha'v'alve constructed in accordance with the practice-of the inven tion, and T Figure 2 is atransve'rse view taken through Figure '1 on the'lin'e 22 looking in the direction indicated by the arrows.-

Referring more particularly to the drawings, Arepresents the cylinder of a rock drill having a'piston chamber B in which is disposed a reciprocatory hammer piston C. The cylinder A has free exhaust ports -D which are controlled in this instance by the pistonC.

A closure is provided for the front end of the piston chamber B in'the form of a front cylinder washer E which has a bore F to slidably receive an extension G of the piston G. The rearward end of the cylinder A is provided'with an enlarged bore H to receive rotation mechanism comprising a rotation ratchet J and the head K of a rifle bar L. The head K is disposed within the rotation ratchet J and carries spring pressed pawls O which are adapted to engage teeth P of v 40 the rotation ratchet J for controlling the direction of rotation of the rifle bar L.

The rifle bar L is provided with the usual flutes Q which may slidably interlock with the piston C in a well known manner for imparting rotary movement to the piston and thus through the medium of suitable chuck mechanism (not shown) to the working implement against which the piston is adapted to strike.

The rotation ratchet J maybe secured in position in any suitable manner. In the present instance it forms a seat for a back head R which may be secured to the cylinder A bymeans of the usual spring pressed side bolts (not shown). .In the construction shown the back head R serves as a closure for the rearward end of the cylinder and forms a housing for a throttle valve S whereby the admissionof pressure fluid into the drill may be controlled. "The throttle valve S maybe of the rotary type and accordingly has a lever T whereby it may be manipulated. "In the "present-instance the throttle valve S'isprovided with a central chamber U which may be in constant communication with a source of pressure fluid supply through a suit- 'able coupling or other device (not shown) In the wall of the throttle valves is a port V which-registers with a passage W in the back head leading to a supply reservoir X in the front orinner end of the back head R.

In accordance with the present invention a valve mechanism designated generally by Y is disposed in the innermost end of the bore H adjacent. the piston chamber B to control the admission of pressure fluid into the ends of the piston chamber.

The valve mechanism comprises a valve chest Z consisting in this instance of plates 5, c and d. The plate (Z is in the form of a back cylinder washer and serves as a closure for the rearward end of the piston chamber B. The plate 0 is interposed between the plates 03' and b and in the plate Z) is formed a valve chamber 6 for the reception of an oscillatory plate distributing valve which has a central fulcrum g whereon said valve is adapted to rock from one limiting position to another.

The valve f has a pair of wings h and j. The wing h in this instance controls the flow of pressure fluid into the rearward end of the piston chamber B through a rearward inlet passage is leading to the rearward end of the piston chamber B and the admission of pressure fluid to the front end of the piston chamber through an inlet passage 0. The inlet passages la and 0 lead from the same end of the valve chamber.

At the right hand end of the valve chamber ie as Figure 1 is viewed in the drawings is a recess p having portions lying on opposite sides of the valve chamber 6 and into this I recess p extends the end of the wing j of the valve. Pressure fluid for actuating the drill is introduced into the recess 7) through ports 9 and a which aflord communication between the recess 1) and a passage .9 leading from the supply reservoir X. The port 9 in this instance is located near the rearward end of the rearward and front sur aces of'thewin-g'j" of the valve. The edge of the wing j is spaced from the wall of the recess p so that a clear ance if exists between the end of the valve and the. outer wall of the recess p. I

At the opposite end of. the valve chamber 6 is a cavity u into which extends the wing it of the valve and a clearance '0 exists between the end oi the wing it and the outer wall of the cavity a so that pressure fluidmay flow over the end of the. wing it from one side of the cavity to the. other- The pressure :fluid for supplying the inlet passages and 0 .is conveyed. to the cavity .14 bya pairofpassages w and a: leading from the valve'chamberc at a point. adjacent the recess-p to the cavity a. The supply passage to in this instance. lies above the valve chamber 6 and the supplypassage. a? lies. below'the valvecchamber e.

The. following is a briet description of the operation of the valve: With the wingjof the valve 7 seated on the plate. was illustrated in Figure l, pressure'fluid flowing through the ports 9 and 0" into the recess p will .fiow over the seated end of the valve. into and through the supply passage on and over the wing it into the cavit u, thence through-the inlet passage is into t 1e rearward end of the piston chamber B to drive the piston C forwardly. During this course of the pressure fluid, the pressure above the wing j may be a trifle. lower than that in the forwardmost part of the. valve chamber e so that pressure fluid will be constantly flowing over the end ofv the Wing j to exert a suction thereon. tending to tilt the. valve. At the. same time the pressure fluid flowing over the wing it will also exert a suction thereon so that when the piston C overruns the port D, these forces acting on the wings of the valve will immediately throw the. valve to its other limiting position- In the absence of means for relieving the compression in the ends of the piston chamber, the compression created during the forward stroke of the piston will flow through the inlet passage 0 to act against the. rearward surface of the wing it for augmenting the forces acting against the wings ot the valve for throwing the valve.

With the valve. in the new position, pressure fluid will flow from the recess. pacross the. forwardv surface of the wing j into the supply passage as thence into the cavity u and over the end of the seated wing it into the in let passage 0 and thence into the front end of the piston chamber B for driving the piston C rearwardly. The compression created in the rearward end of the valve by the piston will then act through the inlet. passage k against: the'tforward surface-of. the wing it. At the same time the pressure fluid flowing from the rearward end of the recess 7 across the end of the wing: j and the' pressurefluid flowingover the-wingfi will exerta -suction on the valve which, together with the compression acting through the inlet passage is, willthrow the valve 1 to its initial position.

I claim:

1. In a" fluid actuated rock drill, the. combination ofa: cylinder and a. piston an -ex haustport.--for the 'cylinder, a valve chest having a valve chamber, inlet passages lead.- ing tron]; the valve. chamber to the cylinder, an. oscillatory plate valve in the valve-chain,- her to control the inlet passages, and ports and passages in the valve chest for conveying pressurefluid overboth. ends-ef'the valve during its course. to the inlet passages, thus exerting, suctiononboth-ends of the valve tending to throwthe valvevfrom one-limiting position to the other. 2.. Irrafiuid actuated reek drill, theeombination ot a cylinder and a piston, an. exhaust port tor the; cylinder,.-a valvechest having a valve chamber, ports in the valve chest afford+ ing communication. between oneend of the valve chamber and 'a source ot-pressure'fluid supply, supply passages in the-valve chest for conveying pressure fluid-from. one end ofthe valve chamber to the other inlet passages leading from the'lastmentioned end of the valve chamberto the cylinder, and a valve in the valve chamber for controlling the inlet openings of the supply and inlet passages.v

8. In a fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest having a valve chamber, ports in the valve chest afiording communication between. oneend of the valve chamber and a source of pressure fluid supply, supply passagesin the valve chest for conveying pressure fluid from one end of the valve chamber to the other, inlet passagesleading. from the last mentioned end of the valve chamber to. the cylinder, and an oscillatory plate valve for controlling the supply passages and the inlet passages, said valve being exposed simultaneously at both ends to the suction of the pressure fluid flowing thereover intothe inlet passages for throwing the valve.

4.. In a fluid actuated'rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest having "a valve chamber, a recess at one end of the valve chamber constantly exposed to pressure fluid, a cavity at the other end of the valve chamber, supply passages in the valve chest for conveying pressure fluid from the recess to the cavity, inlet passages leading from the cavity to the cylinder, and an oscillatory plate valve in the valve chamber for controlling communication between the recess and the supply passages and between the cavity and the inlet passages.

5. In a fluid actuated rock drill, the combi nation of a cylinder and a piston, an exhaust port for the cylinder, a valve chest having a valve chamber, a recess at one end of the valve chamber constantly exposed to pressure fluid, a cavity at the other end of the valve chamber, supply passages in the valve chest for conveying pressure fluid from the recess to the cavity, inlet passages leading from the cavity to the cylinder, and an oscillatory plate valve in the valve chamber having a pair of wings, one of said wings controlling communication between the recess and the supply passages and the other wing controlling communication between the cavity and the inlet passages.

In testimony whereof I have signed this specification.

EARL B. LEAR. 

